A kneader used as a reactor to study a new method for preparation of non-crystal granular starch with principles of high-pressure process,ethanol's protect and heat treatment in mid-content water.It investigated that the effects of reaction temperature,concentration of ethanol,humidity of starch,reaction time and pressure on non-crystal granular corn starch,the structures of treated starch particles were observed by polarizing microscope.The results indicate:when reaction temperature was 80℃,weight ratio of alcohol solution which was the mixture of water and 95% of ethanol(1∶1,m/m)to native starch was 5 to 8 in the airtight environment for 20min,95% of original corn starch particles was converted into amorphous non-crystal granular state which was no need to washing,direct drying and dispersed well.